Document
6-BIT MAGNETIC ANGULAR POSITION ENCODER WITH SERIAL INTERFACE
Key Features
u Up to 64 positions within 360° u Non contact switching u Simple magnet as rotary encoder u Zero position programmable (independent of
magnet orientation)
u Synchronous Serial Interface (SSI) u Cascading is possible u Chip Select Input u Small 8-Pin SOIC (SMT) Package u Temperature Range: -40°C ...+85°C
Ordering Information Part Number Package AS5020 SOIC 8 AS5020T SOIC8 Tape and Reel
General Description The device provides the absolute angular position of a simple magnet that is placed under or above the device’s surface. The device includes the Hall Sensor Array, signal conditioning and post processing needed to generate a 6-bit binary code. The binary code can be easily accessed by a Synchronous Serial Interface (SSI). The angle between the device and the magnetic polarisation axis is exactly represented by one of 64 sectors (of 5.625° each) in the full 360° range. Zero-Position Programming allows one time programming of a specific zero position between the device and the magnet. The initial zero position is shown below.
60
0... initial
4
56
52
α
N S
8
12
48
44
16
20
40
36
24
Functional Block Diagram
32 4mm
28
Rev. n/c
Page 1/11
Feb 2001
6-Bit Magnetic Position Encoder –Data Sheet Rev.1.0
AS5020
Pin Description Pin # 1 Symbol DATA Type DO Description DATA Output of the SSI. If PD/CS=0, the measured angle data (6bit value) is serially shifted out over this pin by the CLK, starting with the MSB. A NVR Bit and a Parity bit are added. (NVR=1 indicates a NonValid Range of the magnetic field.) Even Parity is given. Positive Supply Voltage. Negative Supply Voltage (GND). PROGramming Input. This pin is used to program the zero position into a non-volatile memory (OTP). The programmed value is subtracted from the actual measured angle. Not Connected during operation. This pin is used for testing purposes. Not Connected during operation. This pin is used for testing purposes. Power Down Input, Disable or Chip Select (active low). PD/CS=0 activates the device and enables the measurement. PD/CS=1 sets the device in power save mode and puts the DATA pin in high impedance (highZ) state. CLOCK Input of the SSI. This pin is used to serially clock out the measured angle data at Pin 7 (DATA).
AI: Analogue Input OTP: One Time Programmable
2 3 4
VDD VSS PROG
AI AI DI
5 6 7
N.C. N.C. PD/CS
AI AI DI
8
CLK
DI
DI: Digital Input DO: Digital Output MSB: Most Significant Bit LSB: Least Significant Bit Note: The pins 5 and 6 must not be connected!
Pin Configuration
DATA VDD VSS PROG Rev. n/c Page 2/11
CLK PD/CS N.C. N.C. Feb 2001
6-Bit Magnetic Position Encoder –Data Sheet Rev.1.0
AS5020
Functional Description Measurement Principle A hall sensor array is used to convert the magnetic field distribution above the chip surface into a binary code. Measurement is enabled by PD/CS=0. After each measurement a 6-bit value is latched, with the first falling edge of the CL.